The type of errors returned by envparse's Readers. These fall into 3
categories:
Variables that are unset in the environment.
Variables whose value is empty.
Variables whose value cannot be parsed.
:: a typeCtrl KGHC 9.10.3 · lts/ghc-9.10.x · 248f8f0 · 2026-10-05
Moduleenvparse-0.6.0Haskell2010
This module contains an extensible error infrastructure.
Each kind of errors gets a separate type class which encodes
a Prism (roughly a getter and a constructor). The Readers, then,
have the constraints for precisely the set of errors they can return.
The type of errors returned by envparse's Readers. These fall into 3
categories:
Variables that are unset in the environment.
Variables whose value is empty.
Variables whose value cannot be parsed.
The class of types that contain and can be constructed from the error returned from parsing unset variables.
The class of types that contain and can be constructed from the error returned from parsing variables whose value is empty.
The class of types that contain and can be constructed from the error returned from parsing variable whose value cannot be parsed.